Vendor import of compiler-rt trunk r307894:vendor/compiler-rt/compiler-rt-trunk-r307894

https://llvm.org/svn/llvm-project/compiler-rt/trunk@307894

21 files changed, 441 insertions, 318 deletions

diff --git a/lib/sanitizer_common/CMakeLists.txt b/lib/sanitizer_common/CMakeLists.txt
index bf8459ef5e91..a17bd1299a2c 100644
--- a/lib/sanitizer_common/CMakeLists.txt
+++ b/lib/sanitizer_common/CMakeLists.txt
@@ -6,6 +6,7 @@ set(SANITIZER_SOURCES_NOTERMINATION
   sanitizer_common.cc
   sanitizer_deadlock_detector1.cc
   sanitizer_deadlock_detector2.cc
+  sanitizer_errno.cc
   sanitizer_flags.cc
   sanitizer_flag_parser.cc
   sanitizer_libc.cc
@@ -57,6 +58,7 @@ set(SANITIZER_LIBCDEP_SOURCES
   sanitizer_coverage_libcdep_new.cc
   sanitizer_coverage_win_sections.cc
   sanitizer_linux_libcdep.cc
+  sanitizer_mac_libcdep.cc
   sanitizer_posix_libcdep.cc
   sanitizer_stacktrace_libcdep.cc
   sanitizer_stoptheworld_linux_libcdep.cc
@@ -92,6 +94,8 @@ set(SANITIZER_HEADERS
   sanitizer_common_syscalls.inc
   sanitizer_deadlock_detector.h
   sanitizer_deadlock_detector_interface.h
+  sanitizer_errno.h
+  sanitizer_errno_codes.h
   sanitizer_flag_parser.h
   sanitizer_flags.h
   sanitizer_flags.inc
diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index d44c71513896..89aae579856a 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -107,7 +107,8 @@ bool MprotectNoAccess(uptr addr, uptr size);
 bool MprotectReadOnly(uptr addr, uptr size);
 
 // Find an available address space.
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding);
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found);
 
 // Used to check if we can map shadow memory to a fixed location.
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end);
diff --git a/lib/sanitizer_common/sanitizer_common_interceptors.inc b/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 459530aa95ba..8607bf44902d 100644
--- a/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -40,6 +40,7 @@
 
 #include "interception/interception.h"
 #include "sanitizer_addrhashmap.h"
+#include "sanitizer_errno.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_platform_interceptors.h"
 #include "sanitizer_tls_get_addr.h"
diff --git a/lib/sanitizer_common/sanitizer_errno.cc b/lib/sanitizer_common/sanitizer_errno.cc
new file mode 100644
index 000000000000..a6f9fc6125eb
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_errno.cc
@@ -0,0 +1,35 @@
+//===-- sanitizer_errno.cc --------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno to avoid including errno.h and its dependencies into other
+// files (e.g. interceptors are not supposed to include any system headers).
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_errno_codes.h"
+#include "sanitizer_internal_defs.h"
+
+#include <errno.h>
+
+namespace __sanitizer {
+
+COMPILER_CHECK(errno_ENOMEM == ENOMEM);
+COMPILER_CHECK(errno_EBUSY == EBUSY);
+COMPILER_CHECK(errno_EINVAL == EINVAL);
+
+// EOWNERDEAD is not present in some older platforms.
+#if defined(EOWNERDEAD)
+extern const int errno_EOWNERDEAD = EOWNERDEAD;
+#else
+extern const int errno_EOWNERDEAD = -1;
+#endif
+
+}  // namespace __sanitizer
diff --git a/lib/sanitizer_common/sanitizer_errno.h b/lib/sanitizer_common/sanitizer_errno.h
new file mode 100644
index 000000000000..c405307ba8ec
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_errno.h
@@ -0,0 +1,35 @@
+//===-- sanitizer_errno.h ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno to avoid including errno.h and its dependencies into sensitive
+// files (e.g. interceptors are not supposed to include any system headers).
+// It's ok to use errno.h directly when your file already depend on other system
+// includes though.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ERRNO_H
+#define SANITIZER_ERRNO_H
+
+#include "sanitizer_errno_codes.h"
+#include "sanitizer_platform.h"
+
+#if SANITIZER_FREEBSD || SANITIZER_MAC
+#  define __errno_location __error
+#elif SANITIZER_ANDROID
+#  define __errno_location __errno
+#endif
+
+extern "C" int *__errno_location();
+
+#define errno (*__errno_location())
+
+#endif  // SANITIZER_ERRNO_H
diff --git a/lib/sanitizer_common/sanitizer_errno_codes.h b/lib/sanitizer_common/sanitizer_errno_codes.h
new file mode 100644
index 000000000000..dba774c5b6c5
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_errno_codes.h
@@ -0,0 +1,34 @@
+//===-- sanitizer_errno_codes.h ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno codes to avoid including errno.h and its dependencies into
+// sensitive files (e.g. interceptors are not supposed to include any system
+// headers).
+// It's ok to use errno.h directly when your file already depend on other system
+// includes though.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ERRNO_CODES_H
+#define SANITIZER_ERRNO_CODES_H
+
+namespace __sanitizer {
+
+#define errno_ENOMEM 12
+#define errno_EBUSY 16
+#define errno_EINVAL 22
+
+// Those might not present or their value differ on different platforms.
+extern const int errno_EOWNERDEAD;
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_ERRNO_CODES_H
diff --git a/lib/sanitizer_common/sanitizer_linux.cc b/lib/sanitizer_common/sanitizer_linux.cc
index a94a63c7f16d..a79a2a155db9 100644
--- a/lib/sanitizer_common/sanitizer_linux.cc
+++ b/lib/sanitizer_common/sanitizer_linux.cc
@@ -59,6 +59,14 @@
 #include <ucontext.h>
 #include <unistd.h>
 
+#if SANITIZER_LINUX
+#include <sys/utsname.h>
+#endif
+
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#include <sys/personality.h>
+#endif
+
 #if SANITIZER_FREEBSD
 #include <sys/exec.h>
 #include <sys/sysctl.h>
@@ -209,7 +217,6 @@ static void stat64_to_stat(struct stat64 *in, struct stat *out) {
   out->st_atime = in->st_atime;
   out->st_mtime = in->st_mtime;
   out->st_ctime = in->st_ctime;
-  out->st_ino = in->st_ino;
 }
 #endif
 
@@ -229,7 +236,6 @@ static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
   out->st_atime = in->st_atime_nsec;
   out->st_mtime = in->st_mtime_nsec;
   out->st_ctime = in->st_ctime_nsec;
-  out->st_ino = in->st_ino;
 }
 #endif
 
@@ -815,6 +821,72 @@ bool ThreadLister::GetDirectoryEntries() {
   return true;
 }
 
+#if SANITIZER_WORDSIZE == 32
+// Take care of unusable kernel area in top gigabyte.
+static uptr GetKernelAreaSize() {
+#if SANITIZER_LINUX && !SANITIZER_X32
+  const uptr gbyte = 1UL << 30;
+
+  // Firstly check if there are writable segments
+  // mapped to top gigabyte (e.g. stack).
+  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
+  }
+
+#if !SANITIZER_ANDROID
+  // Even if nothing is mapped, top Gb may still be accessible
+  // if we are running on 64-bit kernel.
+  // Uname may report misleading results if personality type
+  // is modified (e.g. under schroot) so check this as well.
+  struct utsname uname_info;
+  int pers = personality(0xffffffffUL);
+  if (!(pers & PER_MASK)
+      && uname(&uname_info) == 0
+      && internal_strstr(uname_info.machine, "64"))
+    return 0;
+#endif  // SANITIZER_ANDROID
+
+  // Top gigabyte is reserved for kernel.
+  return gbyte;
+#else
+  return 0;
+#endif  // SANITIZER_LINUX && !SANITIZER_X32
+}
+#endif  // SANITIZER_WORDSIZE == 32
+
+uptr GetMaxVirtualAddress() {
+#if SANITIZER_WORDSIZE == 64
+# if defined(__powerpc64__) || defined(__aarch64__)
+  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
+  // We somehow need to figure out which one we are using now and choose
+  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
+  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
+  // of the address space, so simply checking the stack address is not enough.
+  // This should (does) work for both PowerPC64 Endian modes.
+  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
+  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
+# elif defined(__mips64)
+  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
+# elif defined(__s390x__)
+  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
+# else
+  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+# if defined(__s390__)
+  return (1ULL << 31) - 1;  // 0x7fffffff;
+# else
+  uptr res = (1ULL << 32) - 1;  // 0xffffffff;
+  if (!common_flags()->full_address_space)
+    res -= GetKernelAreaSize();
+  CHECK_LT(reinterpret_cast<uptr>(&res), res);
+  return res;
+# endif
+#endif  // SANITIZER_WORDSIZE
+}
+
 uptr GetPageSize() {
 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
 #if SANITIZER_ANDROID
@@ -1599,7 +1671,8 @@ void CheckNoDeepBind(const char *filename, int flag) {
 #endif
 }
 
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found) {
   UNREACHABLE("FindAvailableMemoryRange is not available");
   return 0;
 }
diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index b9a48a1e496b..52196db12731 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -81,28 +81,25 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
 
     // Find the mapping that contains a stack variable.
     MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-    uptr start, end, offset;
+    MemoryMappedSegment segment;
     uptr prev_end = 0;
-    while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
-          /* protection */nullptr)) {
-      if ((uptr)&rl < end)
-        break;
-      prev_end = end;
+    while (proc_maps.Next(&segment)) {
+      if ((uptr)&rl < segment.end) break;
+      prev_end = segment.end;
     }
-    CHECK((uptr)&rl >= start && (uptr)&rl < end);
+    CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
 
     // Get stacksize from rlimit, but clip it so that it does not overlap
     // with other mappings.
     uptr stacksize = rl.rlim_cur;
-    if (stacksize > end - prev_end)
-      stacksize = end - prev_end;
+    if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
     // When running with unlimited stack size, we still want to set some limit.
     // The unlimited stack size is caused by 'ulimit -s unlimited'.
     // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
     if (stacksize > kMaxThreadStackSize)
       stacksize = kMaxThreadStackSize;
-    *stack_top = end;
-    *stack_bottom = end - stacksize;
+    *stack_top = segment.end;
+    *stack_bottom = segment.end - stacksize;
     return;
   }
   pthread_attr_t attr;
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index b48238106dd9..8df01815f9f7 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -191,7 +191,8 @@ void internal_sigfillset(__sanitizer_sigset_t *set) { sigfillset(set); }
 
 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
                           __sanitizer_sigset_t *oldset) {
-  return sigprocmask(how, set, oldset);
+  // Don't use sigprocmask here, because it affects all threads.
+  return pthread_sigmask(how, set, oldset);
 }
 
 // Doesn't call pthread_atfork() handlers (but not available on 10.6).
@@ -799,9 +800,48 @@ char **GetArgv() {
   return *_NSGetArgv();
 }
 
+#if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
+// The task_vm_info struct is normally provided by the macOS SDK, but we need
+// fields only available in 10.12+. Declare the struct manually to be able to
+// build against older SDKs.
+struct __sanitizer_task_vm_info {
+  uptr _unused[(SANITIZER_WORDSIZE == 32) ? 20 : 19];
+  uptr min_address;
+  uptr max_address;
+};
+
+uptr GetTaskInfoMaxAddress() {
+  __sanitizer_task_vm_info vm_info = {{0}, 0, 0};
+  mach_msg_type_number_t count = sizeof(vm_info) / sizeof(int);
+  int err = task_info(mach_task_self(), TASK_VM_INFO, (int *)&vm_info, &count);
+  if (err == 0) {
+    return vm_info.max_address - 1;
+  } else {
+    // xnu cannot provide vm address limit
+    return 0x200000000 - 1;
+  }
+}
+#endif
+
+uptr GetMaxVirtualAddress() {
+#if SANITIZER_WORDSIZE == 64
+# if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
+  // Get the maximum VM address
+  static uptr max_vm = GetTaskInfoMaxAddress();
+  CHECK(max_vm);
+  return max_vm;
+# else
+  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+  return (1ULL << 32) - 1;  // 0xffffffff;
+#endif  // SANITIZER_WORDSIZE
+}
+
 uptr FindAvailableMemoryRange(uptr shadow_size,
                               uptr alignment,
-                              uptr left_padding) {
+                              uptr left_padding,
+                              uptr *largest_gap_found) {
   typedef vm_region_submap_short_info_data_64_t RegionInfo;
   enum { kRegionInfoSize = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64 };
   // Start searching for available memory region past PAGEZERO, which is
@@ -812,6 +852,7 @@ uptr FindAvailableMemoryRange(uptr shadow_size,
   mach_vm_address_t address = start_address;
   mach_vm_address_t free_begin = start_address;
   kern_return_t kr = KERN_SUCCESS;
+  if (largest_gap_found) *largest_gap_found = 0;
   while (kr == KERN_SUCCESS) {
     mach_vm_size_t vmsize = 0;
     natural_t depth = 0;
@@ -821,10 +862,15 @@ uptr FindAvailableMemoryRange(uptr shadow_size,
                                 (vm_region_info_t)&vminfo, &count);
     if (free_begin != address) {
       // We found a free region [free_begin..address-1].
-      uptr shadow_address = RoundUpTo((uptr)free_begin + left_padding,
-                                      alignment);
-      if (shadow_address + shadow_size < (uptr)address) {
-        return shadow_address;
+      uptr gap_start = RoundUpTo((uptr)free_begin + left_padding, alignment);
+      uptr gap_end = RoundDownTo((uptr)address, alignment);
+      uptr gap_size = gap_end > gap_start ? gap_end - gap_start : 0;
+      if (shadow_size < gap_size) {
+        return gap_start;
+      }
+
+      if (largest_gap_found && *largest_gap_found < gap_size) {
+        *largest_gap_found = gap_size;
       }
     }
     // Move to the next region.
diff --git a/lib/sanitizer_common/sanitizer_mac.h b/lib/sanitizer_common/sanitizer_mac.h
index 636d9bfeac8c..3f1c68c8610a 100644
--- a/lib/sanitizer_common/sanitizer_mac.h
+++ b/lib/sanitizer_common/sanitizer_mac.h
@@ -36,6 +36,8 @@ MacosVersion GetMacosVersion();
 
 char **GetEnviron();
 
+void RestrictMemoryToMaxAddress(uptr max_address);
+
 }  // namespace __sanitizer
 
 extern "C" {
diff --git a/lib/sanitizer_common/sanitizer_mac_libcdep.cc b/lib/sanitizer_common/sanitizer_mac_libcdep.cc
new file mode 100644
index 000000000000..c95daa9372ad
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_mac_libcdep.cc
@@ -0,0 +1,30 @@
+//===-- sanitizer_mac_libcdep.cc ------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between various sanitizers' runtime libraries and
+// implements OSX-specific functions.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_MAC
+#include "sanitizer_mac.h"
+
+#include <sys/mman.h>
+
+namespace __sanitizer {
+
+void RestrictMemoryToMaxAddress(uptr max_address) {
+  uptr size_to_mmap = GetMaxVirtualAddress() + 1 - max_address;
+  void *res = MmapFixedNoAccess(max_address, size_to_mmap, "high gap");
+  CHECK(res != MAP_FAILED);
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_MAC
diff --git a/lib/sanitizer_common/sanitizer_platform_limits_posix.cc b/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
index 683f019d70c3..83f4fd22f623 100644
--- a/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -25,7 +25,6 @@
 #endif
 #include <arpa/inet.h>
 #include <dirent.h>
-#include <errno.h>
 #include <grp.h>
 #include <limits.h>
 #include <net/if.h>
@@ -931,14 +930,6 @@ unsigned struct_ElfW_Phdr_sz = sizeof(Elf_Phdr);
   unsigned IOCTL_SNDCTL_DSP_GETOSPACE = SNDCTL_DSP_GETOSPACE;
 #endif // (SANITIZER_LINUX || SANITIZER_FREEBSD) && !SANITIZER_ANDROID
 
-  const int errno_EINVAL = EINVAL;
-// EOWNERDEAD is not present in some older platforms.
-#if defined(EOWNERDEAD)
-  const int errno_EOWNERDEAD = EOWNERDEAD;
-#else
-  const int errno_EOWNERDEAD = -1;
-#endif
-
   const int si_SEGV_MAPERR = SEGV_MAPERR;
   const int si_SEGV_ACCERR = SEGV_ACCERR;
 } // namespace __sanitizer
diff --git a/lib/sanitizer_common/sanitizer_platform_limits_posix.h b/lib/sanitizer_common/sanitizer_platform_limits_posix.h
index 24ffcd7d94f4..63dcd2a6d683 100644
--- a/lib/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/lib/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -1464,9 +1464,6 @@ struct __sanitizer_cookie_io_functions_t {
   extern unsigned IOCTL_PIO_SCRNMAP;
 #endif
 
-  extern const int errno_EINVAL;
-  extern const int errno_EOWNERDEAD;
-
   extern const int si_SEGV_MAPERR;
   extern const int si_SEGV_ACCERR;
 }  // namespace __sanitizer
diff --git a/lib/sanitizer_common/sanitizer_posix.cc b/lib/sanitizer_common/sanitizer_posix.cc
index 63f1bf713b24..8d3128ae199d 100644
--- a/lib/sanitizer_common/sanitizer_posix.cc
+++ b/lib/sanitizer_common/sanitizer_posix.cc
@@ -27,14 +27,6 @@
 #include <signal.h>
 #include <sys/mman.h>
 
-#if SANITIZER_LINUX
-#include <sys/utsname.h>
-#endif
-
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
-#include <sys/personality.h>
-#endif
-
 #if SANITIZER_FREEBSD
 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
 // that, it was never implemented.  So just define it to zero.
@@ -49,80 +41,6 @@ uptr GetMmapGranularity() {
   return GetPageSize();
 }
 
-#if SANITIZER_WORDSIZE == 32
-// Take care of unusable kernel area in top gigabyte.
-static uptr GetKernelAreaSize() {
-#if SANITIZER_LINUX && !SANITIZER_X32
-  const uptr gbyte = 1UL << 30;
-
-  // Firstly check if there are writable segments
-  // mapped to top gigabyte (e.g. stack).
-  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr end, prot;
-  while (proc_maps.Next(/*start*/nullptr, &end,
-                        /*offset*/nullptr, /*filename*/nullptr,
-                        /*filename_size*/0, &prot)) {
-    if ((end >= 3 * gbyte)
-        && (prot & MemoryMappingLayout::kProtectionWrite) != 0)
-      return 0;
-  }
-
-#if !SANITIZER_ANDROID
-  // Even if nothing is mapped, top Gb may still be accessible
-  // if we are running on 64-bit kernel.
-  // Uname may report misleading results if personality type
-  // is modified (e.g. under schroot) so check this as well.
-  struct utsname uname_info;
-  int pers = personality(0xffffffffUL);
-  if (!(pers & PER_MASK)
-      && uname(&uname_info) == 0
-      && internal_strstr(uname_info.machine, "64"))
-    return 0;
-#endif  // SANITIZER_ANDROID
-
-  // Top gigabyte is reserved for kernel.
-  return gbyte;
-#else
-  return 0;
-#endif  // SANITIZER_LINUX && !SANITIZER_X32
-}
-#endif  // SANITIZER_WORDSIZE == 32
-
-uptr GetMaxVirtualAddress() {
-#if SANITIZER_WORDSIZE == 64
-# if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
-  // Ideally, we would derive the upper bound from MACH_VM_MAX_ADDRESS. The
-  // upper bound can change depending on the device.
-  return 0x200000000 - 1;
-# elif defined(__powerpc64__) || defined(__aarch64__)
-  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
-  // We somehow need to figure out which one we are using now and choose
-  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
-  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
-  // of the address space, so simply checking the stack address is not enough.
-  // This should (does) work for both PowerPC64 Endian modes.
-  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
-  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
-# elif defined(__mips64)
-  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
-# elif defined(__s390x__)
-  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
-# else
-  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
-# endif
-#else  // SANITIZER_WORDSIZE == 32
-# if defined(__s390__)
-  return (1ULL << 31) - 1;  // 0x7fffffff;
-# else
-  uptr res = (1ULL << 32) - 1;  // 0xffffffff;
-  if (!common_flags()->full_address_space)
-    res -= GetKernelAreaSize();
-  CHECK_LT(reinterpret_cast<uptr>(&res), res);
-  return res;
-# endif
-#endif  // SANITIZER_WORDSIZE
-}
-
 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
   size = RoundUpTo(size, GetPageSizeCached());
   uptr res = internal_mmap(nullptr, size,
@@ -162,7 +80,7 @@ void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
 }
 
 // We want to map a chunk of address space aligned to 'alignment'.
-// We do it by maping a bit more and then unmaping redundant pieces.
+// We do it by mapping a bit more and then unmapping redundant pieces.
 // We probably can do it with fewer syscalls in some OS-dependent way.
 void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
                                    const char *mem_type) {
@@ -313,13 +231,12 @@ static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 // memory).
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr start, end;
-  while (proc_maps.Next(&start, &end,
-                        /*offset*/nullptr, /*filename*/nullptr,
-                        /*filename_size*/0, /*protection*/nullptr)) {
-    if (start == end) continue;  // Empty range.
-    CHECK_NE(0, end);
-    if (!IntervalsAreSeparate(start, end - 1, range_start, range_end))
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if (segment.start == segment.end) continue;  // Empty range.
+    CHECK_NE(0, segment.end);
+    if (!IntervalsAreSeparate(segment.start, segment.end - 1, range_start,
+                              range_end))
       return false;
   }
   return true;
@@ -327,13 +244,13 @@ bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 
 void DumpProcessMap() {
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr start, end;
   const sptr kBufSize = 4095;
   char *filename = (char*)MmapOrDie(kBufSize, __func__);
+  MemoryMappedSegment segment(filename, kBufSize);
   Report("Process memory map follows:\n");
-  while (proc_maps.Next(&start, &end, /* file_offset */nullptr,
-                        filename, kBufSize, /* protection */nullptr)) {
-    Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
+  while (proc_maps.Next(&segment)) {
+    Printf("\t%p-%p\t%s\n", (void *)segment.start, (void *)segment.end,
+           segment.filename);
   }
   Report("End of process memory map.\n");
   UnmapOrDie(filename, kBufSize);
@@ -363,14 +280,14 @@ void ReportFile::Write(const char *buffer, uptr length) {
 }
 
 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
-  uptr s, e, off, prot;
-  InternalScopedString buff(kMaxPathLength);
   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
-  while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
-    if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
-        && internal_strcmp(module, buff.data()) == 0) {
-      *start = s;
-      *end = e;
+  InternalScopedString buff(kMaxPathLength);
+  MemoryMappedSegment segment(buff.data(), kMaxPathLength);
+  while (proc_maps.Next(&segment)) {
+    if (segment.IsExecutable() &&
+        internal_strcmp(module, segment.filename) == 0) {
+      *start = segment.start;
+      *end = segment.end;
       return true;
     }
   }
diff --git a/lib/sanitizer_common/sanitizer_procmaps.h b/lib/sanitizer_common/sanitizer_procmaps.h
index 5aad6b959ad4..06d072b4dc77 100644
--- a/lib/sanitizer_common/sanitizer_procmaps.h
+++ b/lib/sanitizer_common/sanitizer_procmaps.h
@@ -31,13 +31,37 @@ struct ProcSelfMapsBuff {
 void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
 #endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
 
+// Memory protection masks.
+static const uptr kProtectionRead = 1;
+static const uptr kProtectionWrite = 2;
+static const uptr kProtectionExecute = 4;
+static const uptr kProtectionShared = 8;
+
+struct MemoryMappedSegment {
+  MemoryMappedSegment(char *buff = nullptr, uptr size = 0)
+      : filename(buff), filename_size(size) {}
+  ~MemoryMappedSegment() {}
+
+  bool IsReadable() { return protection & kProtectionRead; }
+  bool IsWritable() { return protection & kProtectionWrite; }
+  bool IsExecutable() { return protection & kProtectionExecute; }
+  bool IsShared() { return protection & kProtectionShared; }
+
+  uptr start;
+  uptr end;
+  uptr offset;
+  char *filename;  // owned by caller
+  uptr filename_size;
+  uptr protection;
+  ModuleArch arch;
+  u8 uuid[kModuleUUIDSize];
+};
+
 class MemoryMappingLayout {
  public:
   explicit MemoryMappingLayout(bool cache_enabled);
   ~MemoryMappingLayout();
-  bool Next(uptr *start, uptr *end, uptr *offset, char filename[],
-            uptr filename_size, uptr *protection, ModuleArch *arch = nullptr,
-            u8 *uuid = nullptr);
+  bool Next(MemoryMappedSegment *segment);
   void Reset();
   // In some cases, e.g. when running under a sandbox on Linux, ASan is unable
   // to obtain the memory mappings. It should fall back to pre-cached data
@@ -47,12 +71,6 @@ class MemoryMappingLayout {
   // Adds all mapped objects into a vector.
   void DumpListOfModules(InternalMmapVector<LoadedModule> *modules);
 
-  // Memory protection masks.
-  static const uptr kProtectionRead = 1;
-  static const uptr kProtectionWrite = 2;
-  static const uptr kProtectionExecute = 4;
-  static const uptr kProtectionShared = 8;
-
  private:
   void LoadFromCache();
 
@@ -67,10 +85,7 @@ class MemoryMappingLayout {
   static StaticSpinMutex cache_lock_;  // protects cached_proc_self_maps_.
 # elif SANITIZER_MAC
   template <u32 kLCSegment, typename SegmentCommand>
-  bool NextSegmentLoad(uptr *start, uptr *end, uptr *offset, char filename[],
-                       uptr filename_size, ModuleArch *arch, u8 *uuid,
-                       uptr *protection);
-  void GetSegmentAddrRange(uptr *start, uptr *end, uptr vmaddr, uptr vmsize);
+  bool NextSegmentLoad(MemoryMappedSegment *segment);
   int current_image_;
   u32 current_magic_;
   u32 current_filetype_;
diff --git a/lib/sanitizer_common/sanitizer_procmaps_common.cc b/lib/sanitizer_common/sanitizer_procmaps_common.cc
index c583f42f25d8..b95f301a437d 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_common.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_common.cc
@@ -119,12 +119,10 @@ void MemoryMappingLayout::LoadFromCache() {
 void MemoryMappingLayout::DumpListOfModules(
     InternalMmapVector<LoadedModule> *modules) {
   Reset();
-  uptr cur_beg, cur_end, cur_offset, prot;
   InternalScopedString module_name(kMaxPathLength);
-  for (uptr i = 0; Next(&cur_beg, &cur_end, &cur_offset, module_name.data(),
-                        module_name.size(), &prot);
-       i++) {
-    const char *cur_name = module_name.data();
+  MemoryMappedSegment segment(module_name.data(), module_name.size());
+  for (uptr i = 0; Next(&segment); i++) {
+    const char *cur_name = segment.filename;
     if (cur_name[0] == '\0')
       continue;
     // Don't subtract 'cur_beg' from the first entry:
@@ -138,11 +136,11 @@ void MemoryMappingLayout::DumpListOfModules(
     //   mapped high at address space (in particular, higher than
     //   shadow memory of the tool), so the module can't be the
     //   first entry.
-    uptr base_address = (i ? cur_beg : 0) - cur_offset;
+    uptr base_address = (i ? segment.start : 0) - segment.offset;
     LoadedModule cur_module;
     cur_module.set(cur_name, base_address);
-    cur_module.addAddressRange(cur_beg, cur_end, prot & kProtectionExecute,
-                               prot & kProtectionWrite);
+    cur_module.addAddressRange(segment.start, segment.end,
+                               segment.IsExecutable(), segment.IsWritable());
     modules->push_back(cur_module);
   }
 }
diff --git a/lib/sanitizer_common/sanitizer_procmaps_freebsd.cc b/lib/sanitizer_common/sanitizer_procmaps_freebsd.cc
index 30216456330e..f0cdbeb4483a 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_freebsd.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_freebsd.cc
@@ -48,36 +48,27 @@ void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
   proc_maps->len = Size;
 }
 
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection, ModuleArch *arch, u8 *uuid) {
-  CHECK(!arch && "not implemented");
-  CHECK(!uuid && "not implemented");
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
   char *last = proc_self_maps_.data + proc_self_maps_.len;
   if (current_ >= last) return false;
-  uptr dummy;
-  if (!start) start = &dummy;
-  if (!end) end = &dummy;
-  if (!offset) offset = &dummy;
-  if (!protection) protection = &dummy;
   struct kinfo_vmentry *VmEntry = (struct kinfo_vmentry*)current_;
 
-  *start = (uptr)VmEntry->kve_start;
-  *end = (uptr)VmEntry->kve_end;
-  *offset = (uptr)VmEntry->kve_offset;
+  segment->start = (uptr)VmEntry->kve_start;
+  segment->end = (uptr)VmEntry->kve_end;
+  segment->offset = (uptr)VmEntry->kve_offset;
 
-  *protection = 0;
+  segment->protection = 0;
   if ((VmEntry->kve_protection & KVME_PROT_READ) != 0)
-    *protection |= kProtectionRead;
+    segment->protection |= kProtectionRead;
   if ((VmEntry->kve_protection & KVME_PROT_WRITE) != 0)
-    *protection |= kProtectionWrite;
+    segment->protection |= kProtectionWrite;
   if ((VmEntry->kve_protection & KVME_PROT_EXEC) != 0)
-    *protection |= kProtectionExecute;
+    segment->protection |= kProtectionExecute;
 
-  if (filename != NULL && filename_size > 0) {
-    internal_snprintf(filename,
-                      Min(filename_size, (uptr)PATH_MAX),
-                      "%s", VmEntry->kve_path);
+  if (segment->filename != NULL && segment->filename_size > 0) {
+    internal_snprintf(segment->filename,
+                      Min(segment->filename_size, (uptr)PATH_MAX), "%s",
+                      VmEntry->kve_path);
   }
 
   current_ += VmEntry->kve_structsize;
diff --git a/lib/sanitizer_common/sanitizer_procmaps_linux.cc b/lib/sanitizer_common/sanitizer_procmaps_linux.cc
index 7e4a44be95b6..1bcad2bf70e6 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_linux.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_linux.cc
@@ -26,41 +26,28 @@ static bool IsOneOf(char c, char c1, char c2) {
   return c == c1 || c == c2;
 }
 
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection, ModuleArch *arch, u8 *uuid) {
-  CHECK(!arch && "not implemented");
-  CHECK(!uuid && "not implemented");
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
   char *last = proc_self_maps_.data + proc_self_maps_.len;
   if (current_ >= last) return false;
-  uptr dummy;
-  if (!start) start = &dummy;
-  if (!end) end = &dummy;
-  if (!offset) offset = &dummy;
-  if (!protection) protection = &dummy;
   char *next_line = (char*)internal_memchr(current_, '\n', last - current_);
   if (next_line == 0)
     next_line = last;
   // Example: 08048000-08056000 r-xp 00000000 03:0c 64593   /foo/bar
-  *start = ParseHex(&current_);
+  segment->start = ParseHex(&current_);
   CHECK_EQ(*current_++, '-');
-  *end = ParseHex(&current_);
+  segment->end = ParseHex(&current_);
   CHECK_EQ(*current_++, ' ');
   CHECK(IsOneOf(*current_, '-', 'r'));
-  *protection = 0;
-  if (*current_++ == 'r')
-    *protection |= kProtectionRead;
+  segment->protection = 0;
+  if (*current_++ == 'r') segment->protection |= kProtectionRead;
   CHECK(IsOneOf(*current_, '-', 'w'));
-  if (*current_++ == 'w')
-    *protection |= kProtectionWrite;
+  if (*current_++ == 'w') segment->protection |= kProtectionWrite;
   CHECK(IsOneOf(*current_, '-', 'x'));
-  if (*current_++ == 'x')
-    *protection |= kProtectionExecute;
+  if (*current_++ == 'x') segment->protection |= kProtectionExecute;
   CHECK(IsOneOf(*current_, 's', 'p'));
-  if (*current_++ == 's')
-    *protection |= kProtectionShared;
+  if (*current_++ == 's') segment->protection |= kProtectionShared;
   CHECK_EQ(*current_++, ' ');
-  *offset = ParseHex(&current_);
+  segment->offset = ParseHex(&current_);
   CHECK_EQ(*current_++, ' ');
   ParseHex(&current_);
   CHECK_EQ(*current_++, ':');
@@ -75,14 +62,12 @@ bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
   while (current_ < next_line && *current_ == ' ')
     current_++;
   // Fill in the filename.
-  uptr i = 0;
-  while (current_ < next_line) {
-    if (filename && i < filename_size - 1)
-      filename[i++] = *current_;
-    current_++;
+  if (segment->filename) {
+    uptr len = Min((uptr)(next_line - current_), segment->filename_size - 1);
+    internal_strncpy(segment->filename, current_, len);
+    segment->filename[len] = 0;
   }
-  if (filename && i < filename_size)
-    filename[i] = 0;
+
   current_ = next_line + 1;
   return true;
 }
diff --git a/lib/sanitizer_common/sanitizer_procmaps_mac.cc b/lib/sanitizer_common/sanitizer_procmaps_mac.cc
index 131017458d4c..560451a16d90 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_mac.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_mac.cc
@@ -88,6 +88,48 @@ void MemoryMappingLayout::LoadFromCache() {
   // No-op on Mac for now.
 }
 
+// _dyld_get_image_header() and related APIs don't report dyld itself.
+// We work around this by manually recursing through the memory map
+// until we hit a Mach header matching dyld instead. These recurse
+// calls are expensive, but the first memory map generation occurs
+// early in the process, when dyld is one of the only images loaded,
+// so it will be hit after only a few iterations.
+static mach_header *get_dyld_image_header() {
+  mach_port_name_t port;
+  if (task_for_pid(mach_task_self(), internal_getpid(), &port) !=
+      KERN_SUCCESS) {
+    return nullptr;
+  }
+
+  unsigned depth = 1;
+  vm_size_t size = 0;
+  vm_address_t address = 0;
+  kern_return_t err = KERN_SUCCESS;
+  mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
+
+  while (true) {
+    struct vm_region_submap_info_64 info;
+    err = vm_region_recurse_64(port, &address, &size, &depth,
+                               (vm_region_info_t)&info, &count);
+    if (err != KERN_SUCCESS) return nullptr;
+
+    if (size >= sizeof(mach_header) && info.protection & kProtectionRead) {
+      mach_header *hdr = (mach_header *)address;
+      if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) &&
+          hdr->filetype == MH_DYLINKER) {
+        return hdr;
+      }
+    }
+    address += size;
+  }
+}
+
+const mach_header *get_dyld_hdr() {
+  if (!dyld_hdr) dyld_hdr = get_dyld_image_header();
+
+  return dyld_hdr;
+}
+
 // Next and NextSegmentLoad were inspired by base/sysinfo.cc in
 // Google Perftools, https://github.com/gperftools/gperftools.
 
@@ -96,40 +138,39 @@ void MemoryMappingLayout::LoadFromCache() {
 // segment.
 // Note that the segment addresses are not necessarily sorted.
 template <u32 kLCSegment, typename SegmentCommand>
-bool MemoryMappingLayout::NextSegmentLoad(uptr *start, uptr *end, uptr *offset,
-                                          char filename[], uptr filename_size,
-                                          ModuleArch *arch, u8 *uuid,
-                                          uptr *protection) {
+bool MemoryMappingLayout::NextSegmentLoad(MemoryMappedSegment *segment) {
   const char *lc = current_load_cmd_addr_;
   current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize;
   if (((const load_command *)lc)->cmd == kLCSegment) {
     const SegmentCommand* sc = (const SegmentCommand *)lc;
-    GetSegmentAddrRange(start, end, sc->vmaddr, sc->vmsize);
-    if (protection) {
-      // Return the initial protection.
-      *protection = sc->initprot;
-    }
-    if (offset) {
-      if (current_filetype_ == /*MH_EXECUTE*/ 0x2) {
-        *offset = sc->vmaddr;
-      } else {
-        *offset = sc->fileoff;
-      }
-    }
-    if (filename) {
-      if (current_image_ == kDyldImageIdx) {
-        internal_strncpy(filename, kDyldPath, filename_size);
-      } else {
-        internal_strncpy(filename, _dyld_get_image_name(current_image_),
-                         filename_size);
-      }
-    }
-    if (arch) {
-      *arch = current_arch_;
+
+    if (current_image_ == kDyldImageIdx) {
+      // vmaddr is masked with 0xfffff because on macOS versions < 10.12,
+      // it contains an absolute address rather than an offset for dyld.
+      // To make matters even more complicated, this absolute address
+      // isn't actually the absolute segment address, but the offset portion
+      // of the address is accurate when combined with the dyld base address,
+      // and the mask will give just this offset.
+      segment->start = (sc->vmaddr & 0xfffff) + (uptr)get_dyld_hdr();
+      segment->end = (sc->vmaddr & 0xfffff) + sc->vmsize + (uptr)get_dyld_hdr();
+    } else {
+      const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
+      segment->start = sc->vmaddr + dlloff;
+      segment->end = sc->vmaddr + sc->vmsize + dlloff;
     }
-    if (uuid) {
-      internal_memcpy(uuid, current_uuid_, kModuleUUIDSize);
+
+    // Return the initial protection.
+    segment->protection = sc->initprot;
+    segment->offset =
+        (current_filetype_ == /*MH_EXECUTE*/ 0x2) ? sc->vmaddr : sc->fileoff;
+    if (segment->filename) {
+      const char *src = (current_image_ == kDyldImageIdx)
+                            ? kDyldPath
+                            : _dyld_get_image_name(current_image_);
+      internal_strncpy(segment->filename, src, segment->filename_size);
     }
+    segment->arch = current_arch_;
+    internal_memcpy(segment->uuid, current_uuid_, kModuleUUIDSize);
     return true;
   }
   return false;
@@ -190,70 +231,7 @@ static bool IsModuleInstrumented(const load_command *first_lc) {
   return false;
 }
 
-// _dyld_get_image_header() and related APIs don't report dyld itself.
-// We work around this by manually recursing through the memory map
-// until we hit a Mach header matching dyld instead. These recurse
-// calls are expensive, but the first memory map generation occurs
-// early in the process, when dyld is one of the only images loaded,
-// so it will be hit after only a few iterations.
-static mach_header *get_dyld_image_header() {
-  mach_port_name_t port;
-  if (task_for_pid(mach_task_self(), internal_getpid(), &port) !=
-      KERN_SUCCESS) {
-    return nullptr;
-  }
-
-  unsigned depth = 1;
-  vm_size_t size = 0;
-  vm_address_t address = 0;
-  kern_return_t err = KERN_SUCCESS;
-  mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
-
-  while (true) {
-    struct vm_region_submap_info_64 info;
-    err = vm_region_recurse_64(port, &address, &size, &depth,
-                               (vm_region_info_t)&info, &count);
-    if (err != KERN_SUCCESS) return nullptr;
-
-    if (size >= sizeof(mach_header) &&
-        info.protection & MemoryMappingLayout::kProtectionRead) {
-      mach_header *hdr = (mach_header *)address;
-      if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) &&
-          hdr->filetype == MH_DYLINKER) {
-        return hdr;
-      }
-    }
-    address += size;
-  }
-}
-
-const mach_header *get_dyld_hdr() {
-  if (!dyld_hdr) dyld_hdr = get_dyld_image_header();
-
-  return dyld_hdr;
-}
-
-void MemoryMappingLayout::GetSegmentAddrRange(uptr *start, uptr *end,
-                                              uptr vmaddr, uptr vmsize) {
-  if (current_image_ == kDyldImageIdx) {
-    // vmaddr is masked with 0xfffff because on macOS versions < 10.12,
-    // it contains an absolute address rather than an offset for dyld.
-    // To make matters even more complicated, this absolute address
-    // isn't actually the absolute segment address, but the offset portion
-    // of the address is accurate when combined with the dyld base address,
-    // and the mask will give just this offset.
-    if (start) *start = (vmaddr & 0xfffff) + (uptr)get_dyld_hdr();
-    if (end) *end = (vmaddr & 0xfffff) + vmsize + (uptr)get_dyld_hdr();
-  } else {
-    const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
-    if (start) *start = vmaddr + dlloff;
-    if (end) *end = vmaddr + vmsize + dlloff;
-  }
-}
-
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection, ModuleArch *arch, u8 *uuid) {
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
   for (; current_image_ >= kDyldImageIdx; current_image_--) {
     const mach_header *hdr = (current_image_ == kDyldImageIdx)
                                  ? get_dyld_hdr()
@@ -291,16 +269,13 @@ bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
 #ifdef MH_MAGIC_64
         case MH_MAGIC_64: {
           if (NextSegmentLoad<LC_SEGMENT_64, struct segment_command_64>(
-                  start, end, offset, filename, filename_size, arch, uuid,
-                  protection))
+                  segment))
             return true;
           break;
         }
 #endif
         case MH_MAGIC: {
-          if (NextSegmentLoad<LC_SEGMENT, struct segment_command>(
-                  start, end, offset, filename, filename_size, arch, uuid,
-                  protection))
+          if (NextSegmentLoad<LC_SEGMENT, struct segment_command>(segment))
             return true;
           break;
         }
@@ -315,28 +290,22 @@ bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
 void MemoryMappingLayout::DumpListOfModules(
     InternalMmapVector<LoadedModule> *modules) {
   Reset();
-  uptr cur_beg, cur_end, prot;
-  ModuleArch cur_arch;
-  u8 cur_uuid[kModuleUUIDSize];
   InternalScopedString module_name(kMaxPathLength);
-  for (uptr i = 0; Next(&cur_beg, &cur_end, 0, module_name.data(),
-                        module_name.size(), &prot, &cur_arch, &cur_uuid[0]);
-       i++) {
-    const char *cur_name = module_name.data();
-    if (cur_name[0] == '\0')
-      continue;
+  MemoryMappedSegment segment(module_name.data(), kMaxPathLength);
+  for (uptr i = 0; Next(&segment); i++) {
+    if (segment.filename[0] == '\0') continue;
     LoadedModule *cur_module = nullptr;
     if (!modules->empty() &&
-        0 == internal_strcmp(cur_name, modules->back().full_name())) {
+        0 == internal_strcmp(segment.filename, modules->back().full_name())) {
       cur_module = &modules->back();
     } else {
       modules->push_back(LoadedModule());
       cur_module = &modules->back();
-      cur_module->set(cur_name, cur_beg, cur_arch, cur_uuid,
-                      current_instrumented_);
+      cur_module->set(segment.filename, segment.start, segment.arch,
+                      segment.uuid, current_instrumented_);
     }
-    cur_module->addAddressRange(cur_beg, cur_end, prot & kProtectionExecute,
-                                prot & kProtectionWrite);
+    cur_module->addAddressRange(segment.start, segment.end,
+                                segment.IsExecutable(), segment.IsWritable());
   }
 }
 
diff --git a/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc b/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
index 36c98d057bd3..747a4a701728 100644
--- a/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc
@@ -43,7 +43,8 @@ void StackTrace::Print() const {
       if (dedup_frames-- > 0) {
         if (dedup_token.length())
           dedup_token.append("--");
-        dedup_token.append(cur->info.function);
+        if (cur->info.function != nullptr)
+          dedup_token.append(cur->info.function);
       }
     }
     frames->ClearAll();
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index 89d9cf61c3e4..de01e8d119a1 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -291,7 +291,8 @@ void DontDumpShadowMemory(uptr addr, uptr length) {
   // FIXME: add madvise-analog when we move to 64-bits.
 }
 
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found) {
   uptr address = 0;
   while (true) {
     MEMORY_BASIC_INFORMATION info;